On Tue, 2 Jul 2013 11:42:14 -0400 Vivek Goyal <vgoyal at redhat.com> wrote: > On Mon, Jul 01, 2013 at 09:32:37PM +0200, Michael Holzheu wrote: > > For zfcpdump we can't map the HSA storage because it is only available > > via a read interface. Therefore, for the new vmcore mmap feature we have > > introduce a new mechanism to create mappings on demand. > > > > This patch introduces a new architecture function remap_oldmem_pfn_range() > > that should be used to create mappings with remap_pfn_range() for oldmem > > areas that can be directly mapped. For zfcpdump this is everything besides > > of the HSA memory. For the areas that are not mapped by remap_oldmem_pfn_range() > > a generic vmcore a new generic vmcore fault handler mmap_vmcore_fault() > > is called. > > > > This handler works as follows: > > > > * Get already available or new page from page cache (find_or_create_page) > > * Check if /proc/vmcore page is filled with data (PageUptodate) > > * If yes: > > Return that page > > * If no: > > Fill page using __vmcore_read(), set PageUptodate, and return page > > > > Signed-off-by: Michael Holzheu <holzheu at linux.vnet.ibm.com> > > In general vmcore related changes look fine to me. I am not very familiar > with the logic of finding pages in page cache and using page uptodate > flag. > > Hatayama, can you please review it. > > Acked-by: Vivek Goyal <vgoyal at redhat.com> Hello Vivek and Andrew, We just realized that Hatayama's mmap patches went into v3.11-rc1. This currently breaks s390 kdump because of the following two issues: 1) The copy_oldmem_page() is now used for copying to vmalloc memory 2) The mmap() implementation is not compatible with the current s390 crashkernel swap: See: http://marc.info/?l=kexec&m=136940802511603&w=2 The "kdump: Introduce ELF header in new memory feature" patch series will fix both issues for s390. There is the one small open discussion left: http://www.mail-archive.com/linux-kernel at vger.kernel.org/msg464856.html But once we have finished that, would it be possible to get the patches in 3.11? Michael